Myopathy is a broad term for a group of neuromuscular disorders characterized by muscle weakness resulting from a dysfunction of muscle fiber. Myopathies can have a genetic link, such as in muscular dystrophies and mytochondrial myopathies; they may be related to metabolic disorders or hormonal imbalances; or they may be acquired, as in the case of common muscle cramps and stiffness.

Treatments vary according to specific conditions and may include drug therapy, physical therapy, braces to support weak muscles or surgery.